Exercise Therapy Modulates Prefrontal Neuroplasticity in Chronic Neck Pain: Insights from fNIRS and Clinical Outcomes

Background: Chronic non-specific neck pain (CNNP) poses a global socioeconomic burden. Although exercise therapy is a cornerstone intervention, its neurophysiological mechanisms remain elusive. This pioneering study applied functional near-infrared spectroscopy (fNIRS) to decode exercise-induced cortical reorganization in CNNP. Methods: Twenty right-handed CNNP patients (54.6±11.5 years; 65% female) completed a 6-week therapeutic exercise program (3 sessions/week). Clinical outcomes (pain [VAS], disability [NDI], kinesiophobia [TSK]) and fNIRS-based cortical hemodynamics were assessed pre/post-intervention. Resting-state functional connectivity (RSFC) and task-evoked activation (during cervical extension) were analyzed in prefrontal regions. Results: Exercise significantly reduced VAS (6.16±1.53 to 1.35±1.23, p<0.001), NDI (32.2±8.55 to 7.15±5.90, p<0.001), and TSK (31.8±4.66 to 22.95±3.10, p<0.001). fNIRS revealed: (1) Enhanced RSFC in the right prefrontal cortex (RPFC; t=2.93, p<0.05); (2) Reduced occipital-DLPFC connectivity (t=–3.44, p<0.05); (3) Increased DLPFC activation (t=2.28, p<0.05) and decreased visual cortex activation (t=–2.19, p<0.05) during task. Clinical improvements correlated with neurophysiological changes: ΔVAS with RPFC activation (r=–0.71), ΔTSK with occipital-DLPFC decoupling (r=0.77) (both p<0.01). Conclusion: Exercise alleviates CNNP symptoms via dual neuroplastic mechanisms: DLPFC hyperactivation (enhancing top-down inhibition) and visual cortex deactivation (reducing sensory hypervigilance). As the first fNIRS study in CNNP, we identify DLPFC HbO↑ and visual cortex HbO↓ as biomarkers for personalized rehabilitation.